Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Comprehensive Income Loss [Line Items]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax	$ 18,773	$ (6,768)	$ (19,280)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized (Gain) Loss Arising During Period, Tax	(6,904)	2,623	7,474
Actuarial (loss)/gain recognized during the period	11,869	(4,145)	(11,806)
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	5,202	4,756	2,724
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Tax	(2,018)	(1,844)	(1,056)
Reclassification adjustments	3,184	2,912	1,668
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Arising During Period, before Tax			(103)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Benefit Plan Improvement, Tax Effect			40
Prior service cost arising during the period	0	0	(63)
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Recognized in Net Periodic Benefit Cost, before Tax	142	103	90
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Recognized in Net Periodic Pension Cost, Tax	(55)	(39)	(35)
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Recognized in Net Periodic Pension Cost, Net of Tax	87	64	55
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, Portion Attributable to Parent	24,117	(1,909)	16,569
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax, Portion Attributable to Parent	(8,977)	740	6,423
Pension liability adjustments, net of tax	(15,140)	1,169	10,146
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	7,600	(300)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(2,900)	(100)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	11,686	(693)	(16,194)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	(9,780)	268	6,278
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	1,906	(425)	(9,916)
Foreign currency translation adjustments, net of tax	(14,502)	0	0
Natural Gas Swap [Member]
Comprehensive Income Loss [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax	(41)	1,267	441
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Tax	16	(491)	(170)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	(25)	776	271
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	248	(628)	(1,229)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(96)	243	476
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	152	(385)	(753)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax, Portion Attributable to Parent	207	639	(788)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax, Portion Attributable to Parent	(80)	(248)	306
Derivative adjustments	127	391	(482)
Interest Rate Swap [Member]
Comprehensive Income Loss [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax		260	1,163
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Tax		(101)	(451)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax		159	712
Derivative adjustments	0	159	712
Corn Option [Member]
Comprehensive Income Loss [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax		(5,486)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Tax		2,129
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax		(3,357)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	7,350	317
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(2,852)	(123)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	4,498	194
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax, Portion Attributable to Parent	1,864
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax, Portion Attributable to Parent	(723)
Derivative adjustments	1,141	194	0
Accumulated Other Comprehensive Income (Loss) [Member]
Comprehensive Income Loss [Line Items]
Pension liability adjustments, net of tax	(15,140)	1,169	(10,146)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	(14,502)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	0
Foreign currency translation adjustments, net of tax	(14,502)
Accumulated Other Comprehensive Income (Loss) [Member] | Natural Gas Swap [Member]
Comprehensive Income Loss [Line Items]
Derivative adjustments	127	391	(482)
Accumulated Other Comprehensive Income (Loss) [Member] | Interest Rate Swap [Member]
Comprehensive Income Loss [Line Items]
Derivative adjustments		159	712
Accumulated Other Comprehensive Income (Loss) [Member] | Corn Option [Member]
Comprehensive Income Loss [Line Items]
Derivative adjustments	$ 1,141	$ 194